The Nitrogen Acceptor in 2H‐Polytype Synthetic MoS 2 : Frequency and Temperature Dependent ESR Analysis

In extending on recent electron spin resonance (ESR) work which has revealed the N acceptor (N substituting for S site) in 2H‐polytype bulk synthetic MoS 2 , the dopant is extensively analyzed in terms of its frequency, temperature ( T ), and magnetic field B angular dependent ESR spectral characteristics. For B ∥ c‐axis, the multi‐frequency analysis confirms the ESR spectrum as being composed of a 14 N hyperfine (hf) triplet with hf splitting constant A ∥ = 14.7 ± 0.2 G ( B ∥ c‐axis) and making up ≈74% of the total spectrum intensity, superimposed on a central line centered at about equal g ‐value [ g ∥ = 2.032(2)]. The presence of the latter signal, points to some non‐uniformity in dopant distribution, that is, clustering, with about ≈26% of the total N response not originating from N incorporated in the preferred “isolated” dopant configuration. Angular dependent measurements reveal distinct anisotropy of the hf matrix, whereas ESR probing over a wide T ‐range exposes drastic signal broadening with increasing T above ≈150 K. Detailed study of the N acceptor signal intensity versus T at Q‐band reveals an activation energy E a = 50 ± 10 meV, herewith consolidating the value reported initially. Besides unveiling the S‐site substitutional N impurity as an appropriate p ‐type dopant for MoS 2 , the total of the ESR work establishes a basic frame of the N acceptor ESR characteristics, giving way for further in‐depth theoretical perusal.